| Message ID | 9407b764-fbf5-ff04-0d27-70d4e9821e37@suse.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On Mon, Feb 06, 2017 at 07:39:09PM -0500, Jeff Mahoney wrote: > Commit 4c63c2454ef incorrectly assumed that returning -ENOIOCTLCMD would > cause the native ioctl to be called. The ->compat_ioctl callback is > expected to handle all ioctls, not just compat variants. As a result, > when using 32-bit userspace on 64-bit kernels, everything except those > three ioctls would return -ENOTTY. > > Fixes: 4c63c2454ef ("btrfs: bugfix: handle FS_IOC32_{GETFLAGS,SETFLAGS,GETVERSION} in btrfs_ioctl") > Cc: stable@vger.kernel.org > Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
--- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -5653,6 +5653,10 @@ long btrfs_ioctl(struct file *file, unsi #ifdef CONFIG_COMPAT long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { + /* + * These all access 32-bit values anyway so no further + * handling is necessary. + */ switch (cmd) { case FS_IOC32_GETFLAGS: cmd = FS_IOC_GETFLAGS; @@ -5663,8 +5667,6 @@ long btrfs_compat_ioctl(struct file *fil case FS_IOC32_GETVERSION: cmd = FS_IOC_GETVERSION; break; - default: - return -ENOIOCTLCMD; } return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
Commit 4c63c2454ef incorrectly assumed that returning -ENOIOCTLCMD would cause the native ioctl to be called. The ->compat_ioctl callback is expected to handle all ioctls, not just compat variants. As a result, when using 32-bit userspace on 64-bit kernels, everything except those three ioctls would return -ENOTTY. Fixes: 4c63c2454ef ("btrfs: bugfix: handle FS_IOC32_{GETFLAGS,SETFLAGS,GETVERSION} in btrfs_ioctl") Cc: stable@vger.kernel.org Signed-off-by: Jeff Mahoney <jeffm@suse.com> --- fs/btrfs/ioctl.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)